Armi Sport 2 band 58 cal musket group

My son in law and I just went out to shoot his new to him used Armi Sport 58 cal musket. It is second hand , but in very good shape. His load was .570 Hornady balls with .017 wet pillow ticking. He tried three different charges, 40, 50, and 60 grains of 2f Goex. We were not impressed by the results, but this was a short day and first time out. He is a good shot with young eyes. My question: Any shooters out there experienced with the Armi Sport? What kind of group did you get or can be expected at 50 and 100 yards?
Thanks
Flinltlocklar :hmm:

Larry, Those rifles are designed for Minie Balls, which means the shallow grooves + three (?) lands don't shoot RB's as well as conicals. That being said, you may want to experiment with RB diameter and patch thickness while staying with 1 powder charge, for the present: 50gr. FFg is what I'd choose. Btw, I once had a Navy Arms .58cal. Harper's Ferry [replica] horse pistol, which shot miserably with Minies (which it was designed for), but impressively with RB's @ 25 yd. I used a .562" RB cast from a Lee Precision mold with a ~.018" - .021" patch. (In those days I wasn't sophisticated enough to measure actual RB diameter or compressed patch thickness.) In short, try thicker and thinner patches with those .570" RB's, lubed with a good patch lube and accuracy is sure to improve

58 caliber.
Put some powder behind that ball.
I did not get decent accuracy with my IA 58 caliber until I got up around 75gr of 2f. It got really good when I reached 85. Those balls are heavy, push them harder...

Yeah, minie rifling with balls... you never know.
My Armisport 1842 likes enough powder to set you back a bit. And it's always seemed to like wheel weight balls better than soft lead.

If you want to shoot Minies you are going to have to slug your bore and find a Minie mold that is .001" - .002" under actual bore diameter. Most people ASSume that a .58 cal rifle will shoot .575" Minies. I have an Armi Sport Zouave that measures .582" and Zoli's that vary from .573" to .585". My J. P. Murray will shoot under 2" @ 50 yds. all day with a RCBS 512 gr. Minie and 48 grs. of 3F.

My limited experience with the Armi Sport mini rifles is quite a number of years in the past but I do remember that they have very good rifling and will shoot a mini extremely well if the shooter chooses the correct fit and a good lube. 35 to 45 grains of 2f, 50 or a little more for hunting. 60 grains is the service load and can get tiring after 25 rounds or so. Their weakest point was the lock and it can be tuned. I nave no idea what to expect from a round ball.

Minie mold that is .001" - .002" under actual bore diameter.

Click to expand...

Thanks, I question undersized as I don't understand the principle. Why not .001 to .002 over? I have shot mini's that are slightly oversized so they don't fall towards the muzzle if one points the barrel down. Never shot enough to make a conclusion about accuracy. More info please
Flintlocklar

Your slightly oversize mini will shoot very well but it'll be a bear to load after the first shot and defeats the purpose of a mini. The mini was developed to provide a projectile that was easy and fast to load which the patched round ball isn't and to take advantage of the accuracy of a rifled gun. The undersized ball gives clearance to be put in the bore and rammed down quickly which can't be done with one that's over bore diameter. With a close fit the mini expands to fully engage the rifling whereas a loose fitting one, say .005" under, won't fully engage or seal and accuracy will suffer but it would be easy to load even in a dirty barrel. As stated above the best fit is .001" to .002" (max in my opinion) under.

BTW Armi Sport barrels need a fairly large diameter mini, .575" would be way too small in my experience. If you plan on shooting minies have a gunsmith or machinist check your bore size. Further I can't stress enough how important a real good lube is.

Larry, a bit tighter patch and ball combination and more powder -- a "swifter kick in the pants" -- would likely help that ball obturate and grip the shallow rifling better. The twist is fine for stabilizing a roundball, but it must be driven hard and get a good grip on its way out.

Larry,
If could, would you check the twist?
On .58 rifling Armisport has done some unexpected things over the years, like put 72" twist in two banders and 48" twist in three banders though the opposite is how the arms might have been originally made.
I'm just curious about what Armisport may have done.

Should you have 72" twist then round ball will perhaps be less likely to "skip" on the rifling.